Here is yet another clever folk toy that uses science to puzzle and amaze
observers. It uses it's potential energy to bob back and forth like a woodpecker.
It was redesigned a bit so that even young kids can help make it. The classic
version usually uses a tiny spring--as from a pen--but we simply use a rubber
band for springyness.
I'd like to know how this project goes for you. I'm happy to answer questions
about it. Feedback from you is an important way for me to know what works and
what needs clarification.